Pius I

Pope Pius I (d. c. 154) was the tenth Bishop of Rome, serving from approximately 142 to 154. According to ancient sources, he was the brother of Hermas, the author of 'The Shepherd,' one of the most widely read Christian texts of the second century. Pius's pontificate occurred during a formative period for the Roman Church as it developed its organizational structure and liturgical practices amid the growing cosmopolitan Christian community in the imperial capital. He is traditionally credited with establishing the date for the celebration of Easter on a Sunday, a decision that would later become a major point of contention between Rome and the Eastern churches in the Quartodeciman controversy.